Stock standard the MLs have a few sections of inch think felty stuff a bit like carpet underlay. It seems to be applied with a double sided tape. There are the obvious screws at the grab handles, coat hooks, sun visors, and then the interior lights have to come out so some screws there. I think there are also some plastic clips that pull out so be a little careful there not to mark the head liner. Plastic trim removal lever is the go there.
My only other tip would be that it is way easier if you can work on it upside down but 99% of people are going to find that pretty well impossible to manage.
The Hitchhiker's guide
to the the Triton universe and NTN.
A how to on finding your own way - search me
The two threads I wish people would use more: thing 1
and thing 2